Electronic control of an ICE, and particularly an "electronic gas pedal", has been previously described, see German Patent Disclosure Document DE-OS No. 31 09 638, to which European Patent Application No. 0 060 326 corresponds. In accordance with this disclosure, the throttle of a vehicular ICE is changed by a positioning motor which is included in a servo motor loop. The operator-controlled gas pedal is coupled to a potentiometer, supplied from a source of electrical energy, so that the position of the gas pedal changes the position of a slider on the potentiometer and, thereby, provides an output signal which is representative of the deflection--if any--of the gas pedal. The gas pedal, thus, functions as a command signal generator which applies a command signal to a comparator. The comparator receives an output signal from a position transducer coupled to the throttle of the ICE and, if a deviation or error signal between the command signal and the actual position signal is detected, the positioning motor is controlled to change the position of the throttle to null the error signal.
Use of an electronic pedal in such a system requires precise positioning of the throttle with a minimum opening of the throttle to permit the engine to operate under idling conditions, and with appropriate idling speed. Should the throttle be moved to a position which is too close towards totally shut-off condition, the engine might stall because its minimum speed may drop below the required idling speed thereof. The throttle must be accurately controlled and, then, it is desirable to provide signals which are representative ofa minimum and a maximum throttle position, so that, by interpolation, intermediate values of the throttle will accurately correspond to the desired throttle positions, as commanded by depression of the throttle, that is, the "gas" pedal.